1. Field of the Invention
The invention is directed to an optically pumped surface-emitting semiconductor laser device having at least one radiation-generating quantum well structure and at least one pump radiation source for optically pumping the quantum well structure, whereby the pump radiation source comprises an edge-emitting semiconductor structure.
2. Description of the Related Art
A semiconductor laser device of the species initially described is disclosed by U.S. Pat. No. 5,991,318. An optically pumped vertical resonator semiconductor laser having a monolithic surface-emitting semiconductor layer structure is disclosed therein. Given this known device, the optical pump radiation, whose wavelength is shorter than that of the generated laser emission, is supplied by an edge-emitting semiconductor laser diode. The edge-emitting semiconductor laser diode is externally arranged such that the pump radiation is beamed obliquely in from the front into the intensification region of the surface-emitting semiconductor layer structure.
A particular problem given this known device is comprise therein that the pump laser must be exactly positioned relative to the surface-emitting semiconductor layer structure and, additionally, requires an optical means for beam focusing in order to image the pump radiation exactly into the desired region of the surface-emitting semiconductor layer structure. These measures involve considerable technological outlay.
In addition to the losses at the optics, moreover, coupling losses also occur that reduce the overall efficiency of the system.
Another problem is comprised therein that only a few quantum wells can be excited by pump radiation due to the pumping from the front.